The analysis of large molecules by mass spectrometry is playing an increasingly important role in modern biological research. Such analysis is facilitated by recent advances in the ability to generate gas-phase ions of these large molecules. Mass spectrometry is particularly suited to the analysis of these biological materials because they are often available only in small quantities, typically as isolates from natural sources. In addition, mass spectrometry is well suited to the area of proteomics, which includes the study of the time-dependent protein complement of an organism.
Large biologically derived molecules are often biopolymers such as proteins, peptides, nucleic acids, oligonucleotides, polysaccharides, and oligosaccharides. The identification and analysis of these biopolymers are dependent on a sufficient amount of fragments, and a sufficient diversity in the fragmentation patterns that may be generated during mass spectrometry. These fragments and fragmentation patterns are interpreted to derive the primary sequence of the biopolymers. Further, the number of and diversity of the fragments generated by mass spectrometry is often dependent upon the number of and diversity of the charges and charge states that may be generated on the molecule. Processes and apparatus for manipulating and modifying these charge states to optimize the observed fragmentation will expand the field of mass spectrometric analysis of biologically derived molecules.